Fig.3 [lower left, 5th bin] shows that in the region were we do not have TPC tracking (photon eta > 1.5) charge particle veto is not efficient, although there is still some improvement from this cut. This probably due to tracks with eta <1.5 which fall into large isolation radius r=0.7.

Yield vs. various analysis cuts

List of cuts (sorted according to bin number in Figs. 1-3. [No SMD sided residual cuts]):

N_events : total number of di-jet events found by the jet-finder

cos(phi_gamma - phi_jet) < -0.8 : gamma-jet opposite in phi

R_{3x3cluster}: Energy in 3x3 cluster of EEMC tower to the total jet energy R_{3x3cluster}>0.9 for Fig. 1, and it is disabled in Fig. 2 and 3

R_EM^jet < 0.9 : neutral energy fraction cut for on away side jet

N_ch=0 : no charge tracks associated with a gamma candidate

N_bTow = 0 : no barrel towers associated with a gamma candidate (gamma in the endcap)

Tow:SMD match : SMD uv-intersection has a tower which is not in a 3x3 cluster

Figure 1: Number of accepted events vs. various analysis cuts The starting number of events (shown in first bin of the plots) is the number of di-jets with reconstructed gamma_pt>7 GeV and jet_pt>5 GeV upper left: cuts applied independently upper right: expept this cut fired (event passed all other cuts and being rejected by this cut)lower left: "cuts applied independently" normalized by the total number of eventslower right: "expept this cut fired" normalized by the total number of events

Figure 2: Same as Fig.1 except: no R_cluster cut and photon detector eta < 1.5 (eta region where we do have most of the TPC tracking)